For harvested species, such as waterfowl, there is an increased probability that a banded bird will be “recovered”, compared to species that are not harvested (e.g., songbirds). The location of a recovered bird and date of recovery, combined with the location and date it was banded, provide information about the general direction the bird traveled and maximum time it was in transit. The pattern of recoveries of ducks from a banding area describe the range that birds from the sample area move, and the migratory route they followed. Current Flyway boundaries were developed in the 1930’s as a result of analyzing such band recovery records, which indicated that waterfowl originating in various breeding regions followed different migration routes to wintering grounds.

• Assessing harvest pressure.

Once populations (i.e., birds that share breeding, migrating, and wintering areas) have been defined, a measure of harvest pressure can be calculated from band recovery data. During each hunting season, a certain number of banded birds are shot, and the bands are reported to the Bird Banding Laboratory. Simple calculations of banded birds reported vs. number of birds banded results in a “recovery rate”. This recovery rate serves as an index to the “harvest rate” (the proportion of the population harvested by hunters). Subsequently, the effects of changes in harvest regulations on harvest rate can be assessed, which result in harvest management decisions consistent with the status of a particular duck population.

• Measuring vulnerability of age and sex classes to harvest pressure.

Most hunters know that it is easier to shoot some species of duck than others. Likewise, it is easier to shoot certain age or sex classes than others within a particular species. When a bird is banded, its species, age and sex are recorded along with the number of the band placed on its leg. Subsequently, when a bird is harvested and the band number reported, the bird's age and sex can be identified. From this information the “relative vulnerability” of different classes can be calculated.

• Estimating production rates.

Managers calculate the actual harvest of ducks by using a “harvest survey questionnaire.” The age ratio of the harvest (young vs. old) often is used as a measure of production. However, the age ratio is a function of production and the vulnerability within and among different species. By correcting the harvest ratio for different vulnerability, an estimate of the true age ratio for fall populations (prior to hunting seasons) can be derived.

• Estimating survival rates of young and adults.

The number of banded birds recovered the first year after banding and in subsequent years can be used to estimate the “survival rates” of both adults and young. Although survival rate estimates are interesting, of more importance is how these rates vary through time as a result of environmental phenomena (e.g., habitat conditions) and harvest management actions. Band recovery data have been the primary source of information used to discern these relationships.